GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - SUMMARY OF CHANGES IN GOODWILL (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Beginning Balance	$ 706,960	$ 702,070
Ending Balance	706,960	706,960
EnerConnex, LLC
Goodwill [Roll Forward]
Goodwill from acquisition at corporate & services segment	$ 0	$ 4,890

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
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-Name Accounting Standards Codification
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